What does Mao Zedong's work under the oil lamp show about the spirit of Mao Zedong?

The scene of Mao Zedong writing an article under an oil lamp shows the spirit of Mao Zedong's selfless work day and night. Because the article "Octagonal Pagoda" in the second grade Chinese is written by Mao Zedong under the oil lamp, this article vividly depicts Chairman Mao's words under the oil lamp in the dead of winter during the hard struggle in Jinggangshan, and shows Chairman Mao's spirit of selfless work day and night to guide the China revolution. Therefore, the scene of Mao Zedong writing an article under the oil lamp shows the spirit of Mao Zedong's selfless work day and night.